“Vernacular architecture can be said to be the ‘architectural language of the people’ with its ethnic, regional, and local ‘dialects.” – Paul Oliver (Author of The Encyclopedia of Vernacular Architecture of the World). Today, steel, concrete, and glass are seen to be the architectural elements of the highest quality whereas adobe, reed, or peat moss are seen to be the forgotten materials. Looking into the facts, these ignored and forgotten materials are more sustainable and apt as per the context.
In a world where today there is research and hunt for sustainable construction techniques using modern materials, checking for strength, stability, and support, the vernacular structures still stand strong and remain environmentally friendly.
As per the study suggests, the key vernacular materials are timber, bamboo, and laterite. The key vernacular construction techniques were found to be timber-frame construction, sun-dried brick wall or Adobe, rammed earth, or Atakpame wall.
The various sustainable construction techniques used in vernacular architecture are as follows:
1. Timber Frame Construction
This technique evolved about a century ago when it began with light wooden framed structures first crafted by the local carpenters. It was a skin made of timber members coated in and out with a sheet.
This process was then practiced at a larger scale and by more people, as with time, there was the availability of cheap machine mail nails, freshly cut and shaped pieces of wood produced by water-powered sawmills.
Timber Frame Construction mainly has three advantages –
- Light in weight, quick to construct as no heavy machinery is required.
- It can be made in any geometric shape and can also be cladded with a variety of materials.
- A huge variety of products as well as tailored structures can be made using this technique.
2. Adobe Construction
Adobe bricks or mud bricks as they are often called, are said to be made of the earth due to their very high content of clay and straw. The earth mix is cast in molds onto the ground which is then let open to dry out under the sun. These bricks are sun-dried, they do not undergo a kiln-fire process.
The first structure to be using this construction technique is dated to 8300BC, some of the buildings around 900 years old, still exist in good shape and are still functional.
This construction technique mainly has the following advantages-
- Adobe bricks are fireproof, durable, and biodegradable.
- They provide sufficient thermal mass to ensure thermal insulation and comfort.
- They have good water resistance and have great flexibility in terms of design-oriented usage.
3. Rammed Earth Construction
The construction technique used in the Great Wall of China and various European castles rammed earth construction dates back thousands of years. Rightly mentioned in the name, this technique involves the use of ‘compressed’ earth.
An amalgamation of earth, mixing the right amount of sand, gravel, and clay is laid into a formwork. This fine mixture is rammed (forced or compressed into place) until it sets to become rock solid. These walls can resist various onslaughts of nature for long durations.
The main advantages of using Rammed Earth Construction are as follows-
- Rammed earth technique has the highest density and the highest compressive strength.
- Durability: Structures constructed using this technique last for thousands of years and remain in good condition for the entire span.
- It ensures superior thermal mass, temperature, and noise control.
4. Thatch Roof Construction
A traditional roofing methodology where dry vegetation such as straw, water reed, rushes, etc. are used to create a roof covering. This covering can vary depending upon the place and their locally available material, for example, Fiji uses palm leaves, Dominica goes with feathered palm leaves roots and Kenya with sugar cane leaf roots.
Thatch not just provides aesthetics but also serves as an environment-friendly sustainable material. Thatch is layered and fixed on top of a rafter-purlin formwork that helps to attain the desired shape and retain its position.
The advantages of thatch roof construction are as follows-
- Thatch is light in weight; hence less amount of timber is required in the roof structure and is easy to manage.
- It does not absorb water and hence helps precipitation runoff.
- It is versatile in terms of covering irregular roof shapes.
5. Wattle and Daub Construction
Wattle and Daub is a method of constructing walls wherein vertical wood stakes are woven with horizontal twigs and then daubed with clay (or mud). Iron Age sites in England have been discovered to have used this methodology of construction and the staves were driven deep into the earth.
This method can also be used as a fill-in for timber-framed structures, this method was used in the houses of England that are now known as half-timbered houses.
Wattle and Daub’s construction has the following advantages-
- It provides high thermal and sound insulation.
- This technique is much lighter in weight when compared to adobe or rammed earth.
- It has a very low carbon footprint.